<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>

  <!-- 引入 layui.css -->
  <link rel="stylesheet" href="//unpkg.com/layui@2.6.8/dist/css/layui.css">

  <!-- 引入 layui.js -->
  <script src="//unpkg.com/layui@2.6.8/dist/layui.js"></script>

  <script type="text/javascript" src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
  <script type="text/javascript" src="js/user.js"></script>
</head>
<body style="text-align: center; /*让div内部文字居中*/
	background-color: #fff;
	border-radius: 20px;
	width: 300px;
	height: 350px;
	margin: auto;
	position: absolute;
	top: 0;
	left: 0;
	right: 0;
	bottom: 0;">
<div id="login" style="text-align: center; margin:auto 0px">
  <input id="uid" type="text" name="title" required lay-verify="required" placeholder="请输入学号" autocomplete="off"
         class="layui-input">
  <input id="pwd" type="password" name="title" required lay-verify="required" placeholder="请输入密码" autocomplete="off"
         class="layui-input">
  <button type="button" class="layui-btn" onclick="login()">登录</button>
</div>
<div id="update" style="display: none">
  <h2 id="uid1"></h2>
  <input id="sid" type="text" name="title" required lay-verify="required" placeholder="请输入座位号" autocomplete="off"
         class="layui-input">
  <button type="button" class="layui-btn" onclick="upd()">修改</button>
</div>

</body>
</html>